scholarly journals Study of the mechanical and chemical properties of potassium manganese phosphate glasses

2018 ◽  
Vol 149 ◽  
pp. 01081 ◽  
Author(s):  
W. Ahmina ◽  
M. El Moudane ◽  
M. Zriouil ◽  
M. Cherraj ◽  
M. Taibi

Homogeneous phosphate glasses having the general formula 20K2O-xMnO-(80-x)P2O5 were synthesized using a melt-quenching method. The amorphous nature of the samples was asserted by X–ray diffraction. The glasses are studied in order to evaluate the influence of MnO addition on the chemical and mechanical properties, such as, dissolution rate, average compressive strength (Rc), Young’s modulus (E) and limit strain (εlim). Some studies show that the addition of MnO significantly reduces the degradation rate (DR) of soluble phosphate glasses and enhanced chemical stability of both alkali-resistance and acid-resistance. MnO interfere with the chemical structure of the glass, and consequently improve their mechanical properties. Indeed, the mechanical measurements showed that the glass structure was modified by the addition of MnO oxide, becoming more rigid, and as a result, increasing the compressive strength (Rc), Young’s modulus (E). These new materials could be an important opportunity for applications in the fields of building, construction, civil engineering, etc…

Author(s):  
Mohammadreza Kamali ◽  
Mahmoud Khalifeh ◽  
Arild Saasen ◽  
Laurent Delabroy

Abstract Integrated zonal isolation is well-known as a key parameter for safe drilling operation and well completion of oil and gas wells. An extensive research on alternative materials has been conducted in the past concerning primary cementing, overcoming annular leaks, and permanent well abandonment. The present article focuses on geopolymers, expansive cement, pozzolan based sealant and thermosetting resins. The viscous behavior and the pumpability of the different materials have been investigated and benchmarked with the properties of neat class G Portland cement. The current study includes short-term mechanical properties of the above-mentioned materials. These properties include compressive strength development, Young’s modulus, indirect tensile strength, and sonic strength. The tests are performed in accordance with API 10B-2 and ASTM D3967-16 for all the materials for 1, 3, 5, and 7-day of curing at 90°C and elevated (172 bar) and atmospheric pressures. Our results show a mixed behavior from the materials. According to uniaxial compressive test results, all the candidate barrier materials developed strength during the considered period; however, the geopolymer and pozzolanic-based mixture did not develop early strength. The expansive cement showed an acceptable early compressive strength, but strength reduction was noticed after some time. The strength reduction of expansive cement was also observed for the indirect tensile strength. All the materials become stiffer overtime as they made more strength. For the neat class G cement and expansive cement, the Young’s modulus showed a minimum after 5 days, but it was increased.


2014 ◽  
Vol 20 (6) ◽  
pp. 541-550 ◽  
Author(s):  
Yujie Quan ◽  
Philipp Drescher ◽  
Faming Zhang ◽  
Eberhard Burkel ◽  
Hermann Seitz

Purpose – The purpose of this paper is to fabricate cellular Ti6Al4V with carbon nanotube (CNT)-like structures by selective electron beam melting and study the resultant mechanical properties based on each respective geometry to provide fundamental information for optimizing molecular architectures and predicting the mechanical properties of cellular solids. Design/methodology/approach – Cellular Ti6Al4V with CNT-like zigzag and armchair structures are fabricated by selected electron beam melting. The microstructures and mechanical properties of these samples are evaluated utilizing scanning electron microscopy, synchrotron radiation X-ray and compressive tests. Findings – The mechanical properties of the cellular solids depend on the geometry of strut architectures. The armchair-structured Ti6Al4V samples exhibit Young’s modulus from 501.10 to 707.60 MPa and compressive strength from 8.73 to 13.45 MPa. The zigzag structured samples demonstrate Young’s modulus from 548.19 to 829.58 MPa and compressive strength from 9.32 to 16.21 MPa. The results suggest that the zigzag structure of the Ti6Al4V cellular solids can achieve improved mechanical properties and the mechanism for the enhanced mechanical properties in the zigzag structures was revealed. Originality/value – The results provide an innovative example for modulating the mechanical properties of cellular titanium by adjusting the unit cell geometry. The Ti6Al4V cellular solids with single-walled CNT-like structures could be used as light-weight construction components or filters in industries. The Ti6Al4V with multiwalled CNT-like structures could be used as new scaffolds for biomedical applications.


2018 ◽  
Vol 5 ◽  
pp. 51-57
Author(s):  
Saroj Phaiju ◽  
Prachand Man Pradhan

The use of Masonry panels in building construction has been popular in most of the parts of the world. However, the use of bricks and brick masonry in different parts of the world being of different nature in terms of quality, size, workmanship of construction, etc. It is yet a topic of interest to researchers to identify the mechanical properties, like Young’s modulus of elasticity and shear modulus of brick masonry panels. It is essential to know the characteristic of brick masonry panels in order to evaluate the responses of masonry walls for any kind of loading. Individual bricks do possess better compressive capacity as compared to masonry walls. Masonry walls are bound together with either mud mortar or by cement sand mortars of various mixes as per the strength requirements. The essential strength properties in engineering are basically the compressive strength and the modulus of elasticity. The American Society for Testing and Materials (ASTM) standard is the most popular for testing bricks and brick masonry for these properties so far. Here, the study has been concentrated in finding the compressive strength of brick, mortar and brick masonry. The study is also done for Young’s modulus of elasticity of brick as well as that of masonry wall. Similarly, the study is extended to find the modulus of rigidity of brick masonry panel. The study is done experimentally for the samples that are generally used in Kathmandu, Nepal. The samples include bricks, cement and sand particularly available in Kathmandu region.


2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Salloom ◽  
S. A. Mantri ◽  
R. Banerjee ◽  
S. G. Srinivasan

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3467
Author(s):  
Anna Nocivin ◽  
Doina Raducanu ◽  
Bogdan Vasile ◽  
Corneliu Trisca-Rusu ◽  
Elisabeta Mirela Cojocaru ◽  
...  

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of etot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 461
Author(s):  
Konrad Kosiba ◽  
Konda Gokuldoss Prashanth ◽  
Sergio Scudino

The phase and microstructure formation as well as mechanical properties of the rapidly solidified Mg67Ag33 (at. %) alloy were investigated. Owing to kinetic constraints effective during rapid cooling, the formation of equilibrium phases is suppressed. Instead, the microstructure is mainly composed of oversaturated hexagonal closest packed Mg-based dendrites surrounded by a mixture of phases, as probed by X-ray diffraction, electron microscopy and energy dispersive X-ray spectroscopy. A possible non-equilibrium phase diagram is suggested. Mainly because of the fine-grained dendritic and interdendritic microstructure, the material shows appreciable mechanical properties, such as a compressive yield strength and Young’s modulus of 245 ± 5 MPa and 63 ± 2 GPa, respectively. Due to this low Young’s modulus, the Mg67Ag33 alloy has potential for usage as biomaterial and challenges ahead, such as biomechanical compatibility, biodegradability and antibacterial properties are outlined.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 529
Author(s):  
Chunzhi Du ◽  
Zhifan Li ◽  
Bingfei Liu

Nanoporous Shape Memory Alloys (SMA) are widely used in aerospace, military industry, medical and health and other fields. More and more attention has been paid to its mechanical properties. In particular, when the size of the pores is reduced to the nanometer level, the effect of the surface effect of the nanoporous material on the mechanical properties of the SMA will increase sharply, and the residual strain of the SMA material will change with the nanoporosity. In this work, the expression of Young’s modulus of nanopore SMA considering surface effects is first derived, which is a function of nanoporosity and nanopore size. Based on the obtained Young’s modulus, a constitutive model of nanoporous SMA considering residual strain is established. Then, the stress–strain curve of dense SMA based on the new constitutive model is drawn by numerical method. The results are in good agreement with the simulation results in the published literature. Finally, the stress-strain curves of SMA with different nanoporosities are drawn, and it is concluded that the Young’s modulus and strength limit decrease with the increase of nanoporosity.


2021 ◽  
Vol 28 (1) ◽  
pp. 343-351
Author(s):  
Norbert Kępczak ◽  
Radosław Rosik ◽  
Mariusz Urbaniak

Abstract The paper presents an impact of the addition of industrial machining chips on the mechanical properties of polymer concrete. As an additional filler, six types of industrial waste machining chips were used: steel fine chips, steel medium chips, steel thick chips, aluminium fine chips, aluminium medium chips, and titanium fine chips. During the research, the influence of the addition of chips on the basic parameters of mechanical properties, i.e., tensile strength, compressive strength, splitting tensile strength, and Young’s modulus, was analyzed. On the basis of the obtained results, conclusions were drawn that the addition of chips from machining causes a decrease in the value of the mechanical properties parameters of the polymer concrete even by 30%. The mechanism of cracking of samples, which were subjected to durability tests, was also explored. In addition, it was found that some chip waste can be used as a substitute for natural fillers during preparation of a mineral cast composition without losing much of the strength parameters.


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